Department of Materials Science and Engineering, McMaster University, Hamilton, ON, L8S 4L7, Canada.
School of Biomedical Engineering, McMaster University, Hamilton, ON, L8S 4L7, Canada.
Sci Rep. 2017 Jan 5;7:39958. doi: 10.1038/srep39958.
Human bone is a complex hierarchical material. Understanding bone structure and its corresponding composition at the nanometer scale is critical for elucidating mechanisms of biomineralization under healthy and pathological states. However, the three-dimensional structure and chemical nature of bone remains largely unexplored at the nanometer scale due to the challenges associated with characterizing both the structural and chemical integrity of bone simultaneously. Here, we use correlative transmission electron microscopy and atom probe tomography for the first time, to our knowledge, to reveal structures in human bone at the atomic level. This approach provides an overlaying chemical map of the organic and inorganic constituents of bone on its structure. This first use of atom probe tomography on human bone reveals local gradients, trace element detection of Mg, and the co-localization of Na with the inorganic-organic interface of bone mineral and collagen fibrils, suggesting the important role of Na-rich organics in the structural connection between mineral and collagen. Our findings provide the first insights into the hierarchical organization and chemical heterogeneity in human bone in three-dimensions at its smallest length scale - the atomic level. We demonstrate that atom probe tomography shows potential for new insights in biomineralization research on bone.
人类骨骼是一种复杂的多层次材料。在健康和病理状态下，为了阐明生物矿化的机制，了解纳米尺度的骨结构及其相应组成至关重要。然而，由于同时描述骨的结构和化学完整性所带来的挑战，纳米尺度上骨的三维结构和化学性质在很大程度上仍未得到探索。在这里，我们首次使用相关透射电子显微镜和原子探针断层成像技术（APT），据我们所知，在原子水平上揭示了人类骨骼的结构。这种方法提供了对骨骼有机和无机成分的化学叠加图谱及其结构。APT 在人类骨骼上的首次应用揭示了局部梯度、Mg 的痕量元素检测以及 Na 与骨矿物质和胶原原纤维的无机-有机界面的共定位，这表明富含 Na 的有机物在矿物质和胶原之间的结构连接中起着重要作用。我们的研究结果首次在三维空间中，在最小的尺度——原子尺度上，提供了人类骨骼的层次组织和化学异质性的见解。我们证明，原子探针断层成像技术在骨骼生物矿化研究方面具有提供新见解的潜力。
